盐酸振荡浸取-原子荧光光谱法测定大米中的痕量镉

Determination of trace cadmium in rice by atomic fluorescence spectrometry with hydrochloric acid oscillating extraction

中文关键词:  盐酸振荡浸取  氢化物发生-原子荧光光谱法  大米  痕量  镉

英文关键词:hydrochloric acid oscillating leaching  hydride generation-atomic fluorescence spectrometry  rice  trace  cadmium

中文摘要:

      目的 建立盐酸振荡浸取原子荧光光谱法测定大米中痕量镉的分析方法。方法 使用体积比为1:1的盐酸溶液振荡快速浸取大米, 在原子荧光光谱仪上, 采用以水为载流的进样方式测定大米中的镉含量。研究优化进样方式后的记忆效应、盐酸酸度、硼氢化钾浓度、镉增敏剂用量及共存离子的影响。结果 Cu2+、Pb2+对镉的测定干扰较为严重, 100 μg/L以上的Cu2+、50 μg/L以上的Pb2+对镉的测定产生负干扰。以水为载流的进样方式无记忆效应, 节省了酸试剂用量。方法检出限为0.75 μg/kg, 相对标准偏差(relative standard deviation, RSD)小于2%, 样品加标回收率为91.6%~100.6%。结论 该方法前处理操作简单、分析速度快、灵敏度高, 适用于大米样品中痕量镉的测定。

英文摘要:

      Objective To establish a method for the determination of trace cadmium in rice by atomic fluorescence spectrometry with hydrochloric acid oscillating extraction. Methods The rice was quickly extracted by 1:1 hydrochloric acid, and cadmium in rice was determined by atomic fluorescence spectrometry with water as carrier current. The memory effect after optimizing injection mode, acidity of hydrochloric acid, concentration of potassium borohydride, dosage of cadmium sensitizer and influence of coexisting ions were studied in detail. Results The interference of Cu2 + and Pb2 + on the determination of cadmium was more serious. Cu2+ above 100 μg/L and Pb2 + above 50 μg/L had negative interference on the determination of cadmium. The injection mode with water as carrier current had no memory effect and saved the amount of acid reagent. The limit of detection cadmium was 0.75 μg/kg, the relative standard deviation (RSD) was less than 2%, and the recoveries were 91.6%?100.6%. Conclusion The method is simple, rapid and sensitive, and suitable for the determination of trace cadmium in rice samples.